Smart Windows Made Smarter

Windows are an important part of any building, as they allow sunlight to enter, as well as some heat. Sometimes we do not want the heat though, which is why researchers are developing smart windows that can control what enters a building. Now researchers at Berkeley Lab have created a new smart-window system with the ability to block visible or near-infrared light.

This new design implants a coating of nanocrystals into the glass. The crystals are made of indium tin oxide, a commonly used transparent conductor, embedded in a matrix of niobium oxide. This combination enables the two electrochromic effects; one for blocking near-infrared light and one for blocking visible light. The researchers also discovered that the two materials interact in such a way as to improve charge to move in and out, which means thinner coatings can be used.

Smart windows built using this technology will have three transparency modes. One mode will let all light through, visible and near-infrared; one mode will block visible and near-infrared; and one mode will block just near-infrared, for when you want the sunlight but not the heat. With as much as a quarter of the total energy the US uses being spent on lighting, heating, and cooling buildings, this new design could prove very useful.